Preparation and characterization of an electronically conductive and chemically modified ultrafiltration type membrane

We have prepared, for the first time, an electronically conductive polyethe rsulfone ultrafiltration membrane, noted as PS, by depositing an ultrathin gold coating. This conductive membrane has been chemically modified by elec trodepositing a polymer-based nickel tetrasulfonated phthalocyanine film (N iTSPc) covered by Nafion(R). Atomic force microscopy (AFM) and membrane pot ential measurement experiments were carried out to characterize the morphol ogy and the transport properties of the new PS membrane, AFM measurements s howed that the topology of the surface pores of the PS membrane was modifie d by the deposition of Au, NiTSPc and Nafion(R) layers and that the chemica l modifications of the membrane do not obstruct the access to the inner por es. Li+ transport number determination have corroborated AFM results and sh owed that the Li+ transport was facilitated by electrostatic effect induced by the negative charge densities of NiTSPc and NiTSPc/Nafion(R) coatings. (C) 2001 Elsevier Science B.V. All rights reserved.